PopCap Games announced today that it's launching a Facebook-only "social adaptation" of the popular Plants vs. Zombies series, dubbed Plants vs. Zombies Adventures. The new game will begin testing in a closed beta release tomorrow, opening up for broader access later this spring.

PvZ Adventures will focus on "road trips" that lead the player through wildly varied settings. Facebook integration will also allow players to track their standing on leaderboards and, in a more interesting twist, send hordes of zombies to attack their friends. Studio head Curt Bererton described it as "the most social, shareable and expansive Plants vs. Zombies experience ever." PopCap says it planned the game as the first in a series of adaptations to the franchise to arrive next year. Plants vs. Zombies 2, the official sequel, is slated to launch early this summer.